Noninvasive systems for blood pressure measurement in arteries

Abstract

Hardware and software methodology are described for a non-invasive approach to blood pressure measurement in pulmonary artery and systemic arteries by using wall displacement and blood velocity that are measured using ultrasound, microwave techniques and/or other radiofrequency (RF) techniques.

The invention claimed is: 
     
       1. A method of blood pressure estimation of a human patient, the method comprising:
 selecting a blood vessel; 
 measuring blood vessel distension and blood velocity with at least one sensor; 
 calculating, in real time, an average blood pressure over a number of cycles based on the measured blood vessel distension and the measured blood velocity using a slope calculated for vessel diameter plotted against the measured blood velocity, wherein the vessel diameter is calculated as the difference between the measured blood vessel distension and an initial diameter (D 0 ) estimate; and 
 displaying the calculated average blood pressure on an electronic display. 
 
     
     
       2. The method of  claim 1 , wherein the blood vessel is a pulmonary or systemic artery. 
     
     
       3. The method of  claim 1 , wherein the calculating includes determining the slope at the beginning of a cardiac cycle. 
     
     
       4. The method of  claim 1 , wherein the blood velocity measured is selected from centerline blood velocity and cross-sectional area average of the velocity. 
     
     
       5. The method of  claim 1 , wherein the Do is estimated with a selection from: a search algorithm, age-corrected allometric equations, diastolic diameter, clinically derived values, and an approximate based on patent history.